InspectAPedia ® | ||||||||||||||||||||||||||
| Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice |
| |||||||||||||||||||||||||
| InspectAPedia Home |
| | Air Conditioning |
| | Electrical | | | Indoor Environment |
| | Exteriors | | | Heating | | | Home Inspection |
| | Insulate Ventilate |
| | Interiors | | | Mold Inspect/Test |
| | Plumbing Water Septic |
| | Roofing | | | Structure | | | Contact Us |
| Directory of Professionals to Inspect or Test a Building | ||||||||||||||||||||||||||
|
ENVIRONMENTAL HAZARDS GUIDE AIR POLLUTANTS, COMMON INDOOR ALLERGEN TESTS for BUILDINGS ALLERGY TESTS for PEOPLE ALLERGY TEST ACCURACY FLOODS IN BUILDINGS-priorities FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP MOLD: A COMPLETE GUIDE TO MOLD MOLD INFORMATION CENTER ACCURACY OF VARIOUS MOLD TEST METHODS Causes of Variation in Airborne Particle Levels Indoor vs. Outdoor Spore Counts Extent of Variation of Airborne Particle Counts Particle Levels vs Sampler Height Particle Levels vs Windows/Doors Particle Levels in Ducts Concentration Bursts of Mold Spores False Negative Results in Mold Tests Mold Culture Plate Test Errors Why Use Airborne Mold/Particle Sampling? Visual Inspection and History for Mold VALIDITY of MOLD TESTING METHODS ACTION GUIDE - WHAT TO DO ABOUT INDOOR MOLD ALLERGEN TESTS for BUILDINGS ALLERGY TESTS for PEOPLE ALLERGY TEST ACCURACY CLEARANCE INSPECTIONS - MOLD CLEANUP DO IT YOURSELF MOLD CLEANUP ENERGY SAVINGS in BUILDINGS ENERGY SAVINGS PRIORITIES ENERGY SAVINGS RETROFIT CASE STUDY ENERGY SAVINGS RETROFIT LEAK SEALING GUIDE ENERGY SAVINGS RETROFIT OPTIONS FIND MOLD in BUILDINGS, HOW TO HIDDEN MOLD INDOOR AIR QUALITY & HOUSE TIGHTNESS INDOOR AIR QUALITY IMPROVEMENT GUIDE INDOOR AIR QUALITY METHODS COMPARED LEAD POISONING HAZARDS GUIDE MOISTURE CONTROL in BUILDINGS MOLD ACTION GUIDE - WHAT TO DO ABOUT MOLD MOLD AGE - Old is the Mold? MOLD APPEARANCE - WHAT MOLD LOOKS LIKE MOLD APPEARANCE - STUFF THAT IS NOT MOLD MOLD ATLAS & PARTICLES INDEX MOLD BY MICROSCOPE MOLD CLASSES, HAZARD LEVELS MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD MOLD REMEDIATION CLEARANCE INSPECTION MOLD DETECTION & INSPECTION GUIDE MOLD DOCTOR? MOLD EXPERT, WHEN TO HIRE MOLD EXPOSURE RISK LEVELS MOLD EXPOSURE STANDARDS MOLD INSPECTORS & MOLD TESTERS MOLD LEVEL IN AIR, VALIDITY MOLD LEVEL REPORTS MOLD LEVELS IN BUILDINGS MOLD by MICROSCOPE MOLD ODORS, MUSTY SMELLS MOLD PREVENTION GUIDE MOLD RELATED ILLNESS GUIDE MOLD RELATED ILLNESS SYMPTOMS MOLD SPRAYS, SEALANTS, PAINTS MOLD STANDARDS MOLD TEST KITS MOLD TEST KITS for DIY MOLD TESTS MOLD TEST PROCEDURES MOLD TEST REASONS MOLD TESTING METHOD VALIDITY Introduction Air samples Shortcomings of air sampling Mold in Air: Quantitative Analysis Tape sampling for mold Determination of mold genera Determination of mold species Shortcomings of tape sampling Vacuum samples Surface vacuuming Shortcomings of surface and carpet vacuuming Vacuuming building cavities Vacuuming exposed insulation Shortcomings of vacuuming insulation Cultures to "Test for Mold" Shortcomings of culturing Swab sampling Shortcomings of swab sampling PCR methods for Mold Identification Mold "Testing" vs. Mold "Problem Identification" Are Mold Test Kits Useful? Reasons to Test for or Identify Mold 1. Save Money if it's Just Cosmetic Mold 2. Mold Related Illness 3. Mold Cleanup Data baseline ODORS, Smells, Gases in Buildings-Diagnosis & Cure RENTERS & TENANTS GUIDE TO MOLD SEWAGE BACKUP TEST & CLEANUP STAIN DIAGNOSIS TECHNICAL & LAB PROCEDURES THERMAL TRACKING More Information InspectAPedia Blog - News Updates Air Conditioning & Heat Pumps Bookstore Electrical Environment Exteriors Heating Home Inspection Insulate Ventilate Interiors Mold Inspect/Test Plumbing Water Septic Roofing Structure Accuracy & Privacy Policies Contact Us |
Here we discuss the advantages and shortcomings of using vacuum cassettes or spore traps to collect mold test samples (or other dust or particle samples) from building wall and ceiling cavities. In this article series discuss the validity of nearly all of the popular mold testing methods currently in use, pointing out the strengths and weakness of each approach to mold sampling in the indoor environment, beginning with air sampling for airborne mold levels indoors. Because mold test validity and mold test accuracy are often confused, readers should also see ACCURACY OF VARIOUS MOLD TEST METHODS. People who need to conduct mold inspection and testing indoors should see MOLD TEST PROCEDURES and TECHNICAL & LAB PROCEDURES. Our MOLD INFORMATION CENTER includes more broad discussions of the overall approach to building investigation, as do many expert references cited at that web. For a more comprehensive collection information about mold test methods see INDOOR AIR QUALITY METHODS COMPARED. For more on "mold classes" (Cosmetic mold vs. allergenic mold vs. toxic or pathogenic mold) see MOLD CLASSES, HAZARD LEVELS and more references such as a Mold Action Guide are at the end of this document. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website. Validity/Accuracy of Vacuuming Building Cavities for a Hidden Mold Screen15th Annual North Carolina/South Carolina Vacuuming building cavities is a popular screening practice to look for mold reservoirs. The investigator is trying to explore wall cavities while doing minimal or no visible damage. A wall-check™ system has been marketed for this purpose and several manufacturers have coped the basic idea: a receiving Air-o-Cel™ or MCE filter cassette is attached at its inlet side to a tube which is inserted as a probe into a wall cavity, permitting creation of only a small hole. The outlet or pump side of the test device is connected to a pump and operated, typically at 15 lpm. Where we have tested this method we have experimented with both passive collection (what most investigators use) or aggressive collection (banging on the wall/ceiling at various points to attempt to dislodge and stir particles). Short duration samples, 1-2 minutes using an Air-o-Cell ™ permit a comparatively large number of samples to be collected in a reasonably short interval. Long duration samples, perhaps for up to two hours, are collected using an MCE filter cassette. Wall Cavity Vacuuming - Found IneffectiveWorking with Louis Relle, a Louisiana mold remediation expert on a New
Orleans Building which was to be demolished we collected wall-check samples from every suspect Building cavity. Shortcomings of vacuuming building cavities through a tube but our testing strongly suggests that this method is very unreliable for characterizing wall contents. We do not believe that enough air movement is created in the wall cavity (sucking any lpm flow through a small diameter tube) to reliably collect what could be a severe mold reservoir that happens not to be right next to the probe. Further if the cavity is insulated there will be virtually no air or particle movement except from very close to the probe. What should we make of wall vacuum test results done without other inspection and testing?
Our photo, left, is not showing the wall-check vacuum method that relies on vacuuming into a cassette through a hole in the wall. Instead, here we have pulled loose paneling and have inserted our spore trap cassette into the cavity. This position combined with aggressive sampling by banging on the wall paneling with a flashlight is more likely to collect problem particles if they are present close to the point of vacuum cassette insertion into the wall. But even this approach is not a reliable characterization of mold risk in the building. And it is not looking into the wall cavity itself - rather we are looking at the two surfaces behind the paneling.
Our photo (left) shows a short-duration but larger surface area or wall opening vacuuming system invented and tested by the author - it did not provide useful results. Longer vacuum pump duration samples for viable sampling (2 hours into an MCE cassette for culturing) still may not move enough air to sample through a cavity, particularly if the cavity is insulated. Further, two-hour samples means that most-likely very few sample points were collected, making the inspection scope extremely limited and thus overall confidence in the accuracy of the picture of the building lower. Consider that the popularly-marketed version of this wall cavity vacuuming approach to test for hidden mold contamination in buildings relies on culture of the sample. Did you know that only about 10% of molds grow in any culture at all? You're 90% uncertain of the accuracy of the test at the outset. One can't be sure that the mold that grew in the culture represents the dominant problem mold or whether it's just a low-occurrence (in the building) spore that liked the media (in the culture). We like cultures for further genera/species identification of samples but we are nervous about relying on them to tell me if the building has a problem or not. ... Technical Reviewers & References
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
MOLD TESTING METHOD VALIDITY
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
| ||||||
| ENVIRONMENTAL HAZARDS GUIDE More Information InspectAPedia Blog - News Updates Air Conditioning & Heat Pumps Bookstore Electrical Environment Exteriors Heating Home Inspection Insulate Ventilate Interiors Mold Inspect/Test Plumbing Water Septic Roofing Structure Accuracy & Privacy Policies Contact Us |
More Information on Building Diagnostic Inspections and Repairs
|
10/26/2009 - 02/21/1987 - InspectAPedia.com/sickhouse/SampMeth_Vacuum2.htm - © 2009 - 1988 Copyright Daniel Friedman All Rights Reserved - InspectAPedia® is a Registered U.S. Trademark